EP2177291B1 - Method for cutting and/or forming of workpieces - Google Patents

Description

The present invention relates to a method according to the preamble of claim 1 for the cutting and / or forming processing of mounted on a workpiece support a machine tool, plate-like workpieces, preferably of sheets, and a computer program product.

Such a method is eg in the DE-A-102006 015 458 disclosed. A flexible cutting and / or forming of metal sheets can with

Help from punching forming machines are made. These machines make it possible to perform different workpiece machining on one and the same machine tool. For example, sheet metal parts can be cut free along the outer contour of the sheet metal composite and also made to this transformations. Such a machine tool is, for example, the TruPunch ^® 5000 offered by Trumpf Werkzeugmaschinen GmbH + Co. KG, which fall Mono tool holders has, that tool holders on each of which a single tool which comprises a tool punch, and a tool die, is stored. Other tools can be changed from a tool magazine demand-dependent in the monowool recordings.

The Monowerkzeugaufnahmen have a liftable by means of a hydraulic lifting drive and lowerable tool punch recording and a fixed tool die recording. For storage of a sheet to be processed is a workpiece table. Workpiece machining takes place by lowering the tool punch receptacle together with a tool punch fixed thereon onto the metal sheet supported on the workpiece table, and as a result the sheet is machined under the action of the tool punch on the one hand and the tool die on the other hand.

In this case occurs on workpieces on which a punching machining is first carried out and which are subsequently to be further formed, for example by roll forming in the area machined by punching, the problem that the already punched contour may be changed by the forming, that is no longer With the original, introduced during punching contour matches. A combined punching and forming machining on one and the same portion of the workpiece can therefore not be done with the desired precision in the manner described above.

FR 2803782 A1 describes a method for forming a fastening tab on a metal plate, wherein the metal plate is first compressed and deformed to form a blind hole forming recess. The bottom of the blind bore forms a metallic disc which is removed to form an open end. To remove the metallic disc, the metal plate is moved from one forming station to another station.

DE 10 2006 015 458 A1 describes a tool device that can be fixed to an industrial robot and is movable with it through the space, as well as a method for forming. In the method, first of all, a formed section is produced in the workpiece at one and the same processing point by means of a forming punch, in order then to introduce a hole into the deformed section by means of a stamping tool integrated into the forming punch.

Task of invention

It is the object of the present invention to develop a method for processing a workpiece in such a way that a formed workpiece can be machined with high precision.

Subject of the invention

This object is achieved by a method with the features of claim 1.

By moving the tool die or the tool punch in a processing position above or below the support plane, a cutting machining can also be performed on formed, up or down over the support plane projecting workpiece areas. For this, e.g. the tool die is raised or lowered until a contact surface of the tool die reaches the bottom of the forming and supports the deformed workpiece area during the application of the tool punch. In this case, first the tool die can be delivered in the processing position before the tool punch is lowered onto the deformed region of the workpiece. Alternatively, a synchronous movement of the tool punch and the tool die is possible in order to machine the workpiece at the machining position. The position of the processing position above or below the workpiece plane or support plane is variable and depends on how far the forming formed on the workpiece or the area to be machined on this over the workpiece level.

The tool die is located in a tool die receptacle and the tool punch is mounted in a tool punch receptacle which are moved toward each other along the stroke axis for machining the workpiece independently of each other. Due to the independent movement of the tool punch and tool die by means of two independent drives, punching machining can be carried out above or below the workpiece level, for example, first the tool die in the machining position is delivered and then lowered to the punching machining the tool dies on the tool die to edit the resting on the support surface of the tool die workpiece.

In a preliminary step, the forming is formed by roll forming on the resting on the workpiece support workpiece. Forming can first be carried out on a single stamping forming machine on one and the same workpiece, and subsequently the deformed region of the workpiece can be processed above or below the support plane as described above. A stamped edit is made on the reshaped area.

In one variant, the tool punch and the tool die are moved to a rest position for moving the workpiece along the workpiece support, in which the tool die does not project upwards and the tool punch does not project down over the support plane. Since the identification of the two tool parts of a tool as a tool punch or tool die on their geometry, especially in forming tools can not be readily made, is understood in the context of this application under the tool punch a tool part, which optionally remains for processing in a fixed position or lowered becomes; The tool die denotes a tool part which is stationary or raised during machining. For positioning a region of the workpiece to be machined-in the present case on the forming-to a position on the workpiece support on which the tool die and the tool punch are arranged, the workpiece can be moved along the workpiece support by means of a coordinate guide. In order to prevent a collision of the workpiece with the tool die or the tool punch in this movement, they can be withdrawn into a rest position in which, for example, the support surface of the tool die is flush with the workpiece support or preferably located below the workpiece support. In order to facilitate the movement of the workpiece along the workpiece support, for example, sliding rollers or a bristle carpet may be provided on this.

In one variant, the method additionally comprises: selecting a tool suitable for machining a given deformation from a linear magazine, and fixing the tool to the tool punch receptacle and to the tool matrix receptacle.

In a further preferred variant, the reaching of the machining position is detected by the tool punch and / or the tool die. Achieving the machining position at which the tool die or the tool punch with a working surface, e.g. can be detected as precisely as possible with a support surface of the tool die or with a cutting edge of the tool punch to allow reliable processing of the workpiece and in particular to prevent the workpiece by the tool punch unintentionally moved beyond the machining position down and possibly additionally deformed or the workpiece is partially lifted by the tool die from the support surface. The detection can be carried out with the aid of a control device, which can access data on the deformations made on the workpiece, in particular on the distance of the underside of the area to be machined relative to the workpiece plane. Additionally or alternatively, sensors, in particular pressure sensors, capacitive sensors, etc. may be provided to monitor the achievement of the machining position by the tool die or the tool punch.

In a further variant, the forming down over the support plane of the workpiece over, wherein the support plane is formed by the top of a formed on a processing table bristle carpet, the bristles are bent down to provide the necessary space for the forming, if the Workpiece is moved in the support plane by means of a coordinate guide.

In a further advantageous variant, when the workpiece is processed in the machining position below the support plane, the tool shaft of the tool punch is arranged above the support plane. The tool shank, ie the area of the tool punch, with this in the tool punch holder is stored, is widened to the outside, so that this area may not be brought into engagement with small-sized transformations. Therefore, it is favorable if the tool punch extends below the support plane only with the punch, which has a smaller width and adjoins the tool shank. In particular, on the machine tool with the aid of the control device, a tool die suitable for machining a predetermined forming can be selected, the punch of which has a length which is greater than the distance between the support plane and the respective machining position below the support plane, ie the length of the punch or the tool punch and the machining position in the stroke direction are coordinated so that the tool shaft remains during machining above the workpiece support.

The object is also achieved by a computer program product having code means which are designed to carry out all the steps of the method described above. A machining program for a workpiece designed for carrying out the method can be created long before the workpiece is processed and transmitted to a control unit of the machine tool just before machining by means of a computer-readable medium or by means of another form of data transmission Processing works.

The method described above can be carried out by means of a machine tool not belonging to the invention, which has a control unit which is designed / programmed for machining the tool punch and the tool die along a deformation of the workpiece projecting upwards or downwards over a contact plane on the workpiece support to move the lifting axis in a processing position above or below the support plane. When punching processing above or below the support plane or workpiece plane, the tool die is usually first delivered in the processing position and then the tool die is lowered onto the stationary tool die. Alternatively, it is also possible to perform an example punching machining by the tool die is pressed with a lifting movement from below against the stationary tool punch or by both the tool punch as well as the tool die are simultaneously moved towards each other along the stroke axis.

Such a machine tool may further comprise: a tool punch receptacle for supporting the tool punch, a tool die receptacle for mounting the tool die, and a tool drive, by means of which the tool punch receptacle and the tool die receptacle are movable along the lifting axis. The tool drive can comprise two separately controllable drive units for the tool punch holder or the tool die holder. The tool punch receptacle and the tool die receptacle can in this case be designed as monowool receptacles on which either different tools can be fixed or stored.

The tool die can be designed in the shape of a pyramid or truncated cone and has a bearing surface for the workpiece on the top surface. Such a geometry of the tool die is favorable in order to avoid a collision with the edge regions of the forming when the tool die is raised above the workpiece plane, before the tool die reaches the machining position. The tool die is designed for this purpose higher than ordinary tool dies and with a smaller contact surface, with the geometries described above have proven to be particularly advantageous. It is understood that the tool die can also have a different, in particular asymmetrical geometry and that the geometry of the tool die can be adapted to the geometry of the forming to be processed. If a punching die is used as the tool die, one or more openings for engagement with a punch can be formed on the top surface.

The above-described machine tool may include a sensor unit for detecting the reaching of the machining position by the tool punch and / or by the tool die. The sensor unit may have one or more pressure sensors, optical sensors, etc. Capacitive sensors for measuring the potential between the workpiece and the tool die or tool dies are also possible. The measured data supplied by the sensors can are compared with the data stored in the control unit on the type and size of the forming before the machining of the workpiece is performed.

Further advantages of the invention will become apparent from the description and the drawings. Likewise, the features mentioned above and the features listed further can be used individually or in combination in any combination. The embodiments shown and described are not to be understood as exhaustive enumeration, but rather have exemplary character for the description of the invention.

Fig. 1

eine schematische Darstellung einer Werkzeugmaschine zum schneidenden und/oder umformenden Bearbeiten von Werkstücken, und

Fign. 2a-c

schematische Darstellungen von drei Schritten zum stanzenden Bearbeiten an einer Umformung nach oben an dem Werkstück von Fig. 1, und

Fign. 3a-c

schematische Darstellungen von drei Schritten zum Bearbeiten einer Umformung nach unten an dem Werkstück von Fig. 1.

Show it:

Fig. 1

a schematic representation of a machine tool for the cutting and / or forming machining of workpieces, and

FIGS. 2a-c

schematic representations of three steps for punching processing on an upwards forming on the workpiece of Fig. 1 , and

FIGS. 3a-c

schematic representations of three steps to edit a down to the workpiece of Fig. 1 ,

Fig. 1 shows a machine tool 1 for cutting and / or forming plate-like workpieces in the form of a stamping / forming machine for processing sheets. The punching / forming machine 1 has a C-shaped machine frame 2, in the throat area of which a workpiece support 3 designed as a workpiece support is arranged, which serves for supporting a workpiece to be machined in the form of a sheet 4. On its upper side, the workpiece table 3 forms a horizontal support plane 5 for the sheet 4 to be processed, which is parallel to the x / y plane of the in Fig. 1 shown coordinate system runs. By means of a coordinate guide 6, the clamping device 7 clamped sheet 4 in the support plane 5 of the workpiece table 3 is displaced.

At the front end of the upper leg of the C-shaped machine frame 2, a tool punch receptacle 8 is arranged, in which a tool punch 9 is mounted. Furthermore, a tool die receptacle 10 is provided at the front end of the lower leg of the C-shaped machine frame 2, in a tool die 11 is mounted. The tool punch 9 and the tool die 11 form a tool 12 for the separating and / or deforming machining of the sheet 4 .

A drive unit of the punching / forming machine 1 is formed by a punch drive 13 and a die drive 14 in the form of linear drives. By means of the punch drive 13, the tool punch receptacle 8 together with the tool stamp 9 mounted thereon and fixed along a lifting axis 15 relative to the workpiece table 3 can be raised and lowered. In a comparable manner, the tool die holder 10 together with the tool die 11 mounted or fixed therein can be raised and lowered by means of the die drive 14 along the lifting axis 15 with respect to the workpiece table 3. Furthermore, the tool punch receptacle 8 and the tool die receptacle 10 are rotationally adjustable by means of a rotary drive not shown in detail about an identical with the lifting axis 15 tool axis of rotation 16.

At the coordinate guide 6, a linear magazine 17 is provided with further tools 12. The tools 12 located in the linear magazine 17 are each held by a tool cassette 18 and can be fixed to the tool punch receptacle 8 or the tool die receptacle 10 as required for machining the sheet 4.

During tool change and during workpiece machining, all drives of the stamping and forming machine 1 are controlled by means of a numerical control unit 21 . The numerical control unit 21 comprises, in particular, memory means 19 for storing tool data and control means 20 for detecting both the raising, lowering and rotating movements of the tool punch receptacle 8 and the raising, lowering and rotating movements of the tool die receptacle 10 based on FIGS stored data on the workpiece 4 and the tool 12 to measure and control.

The following is based on the FIGS. 2a c describes the process of punching machining of the workpiece 4 on a bead-shaped deformation 22 protruding upward over the support plane 5. Forming 22 was performed on the Workpiece 4 formed in a previous step by roll forming by means of a forming tool, which subsequently as shown above against the in FIGS. 2a-c shown punching tool 9, 11 has been replaced.

As in Fig. 2a is indicated by an arrow, the workpiece 4 for the punching processing is first moved by means of the coordinate guide 6 in the support plane 5 of the workpiece table 3 until the punching machined region of the deformation 22 is positioned over the punching die 11. During this movement, the pyramid-shaped or conically shaped punching die 11 is in a rest position R in the Z direction (direction of gravity), in which a bearing surface 23 formed on the top surface of the punching die 11 is flush with the workpiece plane 5. The tool punch 9 also assumes a rest position R above the workpiece support 5.

As in Fig. 2b is shown, the punching die 11 is subsequently raised until it reaches a machining position B in the Z direction, at which the support surface 23 of the punching die 11 reaches the underside of a planar region of the deformation 22 to be machined. The tool die 11 is in this case delivered by the control device 21 in the processing position B, ie, the movement along the lifting axis 15 is stopped as soon as the support surface 23 has reached the bottom of the deformation 22. The achievement of the machining position B by the punching die 11 or the bearing surface 23 can be achieved in a sensor unit 26 of the machine tool (cf. Fig. 1 ) are determined, for example via pressure sensors or optical sensors, but it is also possible that the control unit 21 based on the data known about the deformation of the workpiece 4 determines the required to reach the machining position B stroke of the Werkzeugmatrize 11 without the aid of sensors.

As in Fig. 2b can also be seen, the punching die 11 is in this case matched to the geometry of the deformation 22, that this can be raised above the work piece level 3, without causing a collision with the workpiece 4, before the punching die 11 has reached the processing position B. , For this purpose, both the size of the support surface 23 and the angle that a lateral surface 25 of the punching die 11 with the support surface 23 and der Sheet metal plane 5 includes (in the present case about 45 °, typically between about 20 ° and about 80 °) chosen so that the lateral surface 25 of the punching die 11 can not collide with the edge regions of the deformation 22 before the support surface 23 the achieved to be machined region of the deformation 22. A suitable for the processing of a given deformation 22 tool 12 is selected here by the control unit 21 from the linear magazine 17 and as described above in the tool die holder 10 and the tool punch holder 8 set.

At the area of the deformation 22 resting on the support surface 23 in the processing position B, punching processing is subsequently carried out by the punch 9 being lowered onto the punching die 11 and in this case brought into engagement with an opening 24 provided on the support surface 23, cf. Fig. 2c , After the punching processing, in which the punch 9 can work the workpiece 4 with several punching strokes, the punching die 11 can again in the in Fig. 2a shown rest position R are spent to edit the workpiece 4 at another location.

It is understood that the punching die 11 does not necessarily have to be delivered in the processing position B, but that, in particular in the event that further transformations are to be made up or down on the region to be processed, the tool die 11 is raised and at the same time the tool die 9 can be lowered to reshape the workpiece 4 above the workpiece support 3.

In FIGS. 3a c shows a machining process on a workpiece 4 , in which the deformation in contrast to in FIGS. 2a-c shown workpiece 4 is not up, but down over the support plane 5 of the workpiece 4 protrudes. In this case, the support plane 5 of the workpiece 4 is formed by the top of a formed on the machining table 3 bristle carpet 3a , the bristles are bent down to provide the necessary space for the forming 22 when the workpiece 4 in the support plane 5 by the coordinate guide 6 is moved. Otherwise, the machining process runs in the same way as in FIGS. 2a-c described processing process, with the difference that the Machining position B is not above, but below the support plane 5 in the workpiece support 3, so that the punch 9 must be spent to edit the deformation 22 under the support plane 5. In this case, the stamp shank 9a remains, with which this on the tool punch receptacle 8 (see. Fig. 1 ) is stored, above the support plane 5, to allow the engagement of the punch formed on the punch 9 or of its cutting edge in the deformation 22, without the punch shaft 9a acts as a disturbing contour.

It is understood that in addition to the in FIGS. 2a-c respectively. Fig. 3a-c shown transformations in the form of a bead, as they are typically generated by roll forming, other, eg gill-like transformations can be made by means of suitable forming tools on the workpiece 4. Also, such transformations can be processed in the manner described above above or below the workpiece level 5. Overall, in the manner described above, a stamping and / or forming machining can also be carried out in upwardly or downwardly formed partial regions of a workpiece with high precision. It is understood that in this case also possibly the role of punch 9 and die 11 in comparison to in FIGS. 2a-c respectively. FIGS. 3a-c shown arrangement can be reversed, ie the punch 9 is below, the die 11 is disposed above the support plane 5.

Claims (7)

1. A method for processing plate-like workpieces (4), preferably metal sheets, supported on a workpiece support (3) of a machine tool (1) by cutting and/or forming, comprising:

   processing the workpiece (4) by moving a tool punch (9) and a tool die (11), which form a tool (12) for processing by separating and/or forming, along a stroke axis (15) into a processing position (B) above or below a support plane (5) on the workpiece support (3) in order to process the workpiece (4) by punching at a crimp-shaped formed shape (22) projecting upwards or downwards beyond the support plane (5), wherein the tool die (11) is supported in a tool die holder (10) and the tool punch (9) is supported in a tool punch holder (8), which holders are moved towards each other along the stroke axis (15) independently of each other for processing of the workpiece (4), wherein the tool die holder (10) and the tool punch holder (8) are designed as tool holders to which different tools (12) can selectively be fixed, characterized in that in a previous step, the crimp-shaped formed shape (22) is made in the workpiece (4) resting on the workpiece support (3) by roll-forming using a forming tool and wherein, prior to processing of the workpiece (4) by punching on the formed shape (22), the forming tool is exchanged with the tool (12).
2. A method according to claim 1, in which, for movement of the workpiece (4) along the workpiece support (3), the tool punch (9) and the tool die (11) are taken to a home position (R) in which the tool die (11) does not project upwards and the tool punch (9) does not project downwards beyond the support plane (5).
3. A method according to any one of the preceding claims, wherein the method further comprises:

   selecting a tool (12) that is suited for processing a predetermined formed shape from a linear magazine (17) and fixing the tool (12) to the tool punch holder (8) and to the tool die holder (10).
4. A method according to any one of the preceding claims, in which the attainment of the processing position (B) by the tool punch (9) and/or the tool die (11) is detected.
5. A method according to any one of the preceding claims, in which the formed shape (22) projects downwards beyond the support plane (5) of the tool (4), wherein the support plane (5) is formed by the upper side of a bristle carpet (3a) formed on a processing table (3), the bristles of which are bent downwards in order to provide the required free space for the formed shape (22) when the workpiece (4) is displaced in the support plane (5) by means of a coordinate guidance (6).
6. A method according to any one of the preceding claims, in which, when the workpiece (4) is being processed in the processing position (B) below the support plane (5), the tool shank (9a) of the tool punch (9) is disposed above the support plane (5).
7. A computer program product which has code means adapted to perform all steps of the method according to any one of claims 1 to 6.

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